What the standard defines
ISO 518 defines the accessory shoe’s dimensions and the center sync contact.
What it does not promise
Extra contacts for TTL, HSS and menus are proprietary. Canon’s newer multi-function shoe, used by the Speedlite EL-5, is one example.
Mirrorless notes
Many manual flashes fire only with the mechanical shutter, as NEEWER notes for the TT560.
How to check before buying
Check whether the flash is single-contact manual or TTL for your brand, and whether your camera has the shoe it needs.
What people ask before they commit
Will any flash fire on my camera?
A single-contact manual flash fires from the center contact on most cameras. TTL needs the camera brand’s contacts or a matching module.
What is X-sync speed?
The fastest shutter speed at which the whole frame is open when the flash fires, often around 1/200 s. Above it, use HSS.
What is a PC sync port?
A small socket for a sync cable, as on the [FocusFoto CY-20](/reviews/on-camera-flashes-focusfoto/).
Last reviewed November 2, 2026